The present disclosure relates broadly and generally to a mesh screen assembly and shield cup for a gas shielded electric arc torch (e.g. for welding or cutting).
Gas tungsten arc welding (GTAW), also known as tungsten inert gas (TIG) welding, is an arc welding process that uses a non-consumable tungsten electrode to produce the weld. The weld area is protected from atmospheric contamination by an inert shielding gas, such as argon or helium. A filler metal is also normally used, although some welds, known as autogenous welds, do not require it. A constant-current welding power supply produces electrical energy, which is conducted across the arc through a column of highly ionized gas and metal vapors known as a plasma.
Prior art GTAW torches may also utilize a gas lens which together with a collet helps hold the tungsten electrode in place, and creates the electrical contact necessary for proper current transfer. A typical gas lens comprises a copper and/or brass body with layered mesh screens of stainless steel. The gas lens functions to helps evenly distribute the shielding gas promoting a laminar flow around the tungsten and along the weld puddle and arc.